If you are fully sheeting the model, then I would consider using tissue and dope as a finish. That is a good finish for up to .15 or so models that are fully sheeted and if done properly, it can be lighter than iron-on's such as Monokote and will look tons better.
Also, if you have an airbrush, then use Tamiya acrylics for color and then use an appropriate fuel-proof flat clear top coat. You'll be much more pleased with this result than if it looks like plastic. OK, maybe you won't be but I would be.
